U.S. Pat. App. Pub. No. 2008/0090337, entitled “Electrically Actuated Switch,” to R. Stanley Williams describes a switch that changes between high-conductivity state and a low-conductivity state as a result of internal ion movement. The switch can effectively act as a memristor having a memristance that depends on the total current that has passed through the switch. Operation of these types of switches generally rely on behavior of nanoscale materials, particularly, the interaction of a primary material such as titanium dioxide (TiO2) and a source material such as TiO2-x that contains dopants (e.g., oxygen vacancies). When the primary material and the source material are between two electrodes and a sufficient bias voltage is applied, an electric field can move dopant ions between the primary material and the source material and can drastically change the electrical characteristics of the primary material. In particular, dopant ions flowing into an intrinsic primary material make the primary material significantly more conductive, and dopant ions flowing out of the primary material can return the primary material to its intrinsic non-conductive state.
In another area of technology, many circuits such as multiplexers, volatile and non-volatile memories, video displays, and imaging and detector arrays commonly require decoding circuits that can decode a multi-bit address signal and select a device or a signal line. Signals can then be applied to or received from the selected device or signal line, for example, for operations such as reading or writing of data or simply to direct a signal to or from the correct target. A variety of circuits implementing address decoding are known to accommodate both multi-bit addresses that are transmitted in parallel on multiple lines of an address bus and multi-bit addresses that are serially transmitted on a single line. Typically, decoders for serial address signals use latches, flip-flops, or other storage devices to retain address bits that are then applied in parallel to decoding logic.
Use of the same reference symbols in different figures indicates similar or identical items.